1. Field of Invention
This invention pertains generally to the detection of pesticides and, more particularly, to a handheld instrument and method which are particularly suitable for detecting pesticides on lettuce and other produce.
2. Related Art
Organic farming has been one of the fastest growing segments of American agriculture in recent years, and many people prefer organic produce because of its superior taste and quality. Organic farmers are not allowed to use synthetic pesticides or fertilizers, and organically grown produce contains significantly lower levels of pesticide residues than conventionally grown produce. With its more stringent growing requirements, popularity among consumers, and relatively limited availability, organic produce generally commands a higher price than conventional produce.
Organic produce is currently checked for pesticide residue by washing the produce with water and then sending a sample of the water to a laboratory for analysis. That is a time consuming and expensive process and one which is not suitable for in situ checking to see if a given load of produce has, in fact, been organically grown.
Heretofore, there have been some attempts to provide portable instruments for checking produce for the presence of pesticide residue through fluorescence spectroscopy in the field. Such attempts still require the use of an aqueous sample which is placed in a cuvette and analyzed in a spectrometer. While such instruments avoid the need to send the sample to a laboratory, the use of the aqueous sample is still time consuming and cumbersome.